Silver halide developer compositions containing polyoxyalkylene ethers of hexitol ring dehydration products



Patented Dec. 12, 1950 SILVER HALIDE DEVELOPER COMPOSI- TIONS CONTAINING POLYOXYAL- KYLENE ETHERS OF HEXITOL RING DEHYDRATION PRODUCTS Ralph Kingsley Blake, Rochester, N. Y., assignor to E. I. du Pont de Nemours & Company, Wilmington, Del., a corporation of Delaware No Drawing. Application June 10, 1947, Serial No. 753,820

9 Claims.

This invention relates to photography. More particularly, it relates to novel photographic developer compositions and to processes of developing silver halide images therewith.

An object of this invention is to obtain improved silver images. Another object is to provide improved processes for the development of silver halide images. A further object is to provide improved photographic developer solutions. A still further object is to provide novel developer compositions which produce enhanced speed and contrast results in the development of silver halide images. Still other objects will be apparent from the following description of the invention.

It has been found that the inclusion of the polyoxyalkylene ethers of hexitol ring dehydration products in photographic developer solutions leads to beneficial changes in the effective photographic emulsion speed of exposed silver halide emulsion layers and the contrast of the developed images. The compounds can be used in various amounts, e. g., from 0.1 to 2.5 grams of the ethers per liter of developer solution. With most of the ethers, however, the optimum concentration is about 0.5 gram per liter.

The polyoxyalkylene ethers of hexitol ring dehydration products are commercially available. They are essentially non-ionic in character and have been found to have good wetting and disa persing properties. They can be made by reacting a hexitol ring dehydration product, such as a hexitan or a hexide, with an alkylene oxide, e. g., ethylene oxide or propylene oxide, in an amount sufficient to introduce a plurality of oxyalkylene groups into the molecule. For instance, the reaction may be carried out in a manner similar to that described in British Patent No. 443,559 and United States Patent 2,380,166. In general, the alkylene oxide should be used in an amount sufficient to form an ether group on one of the oxygen atoms of the hydroxyl groups of the hexitan or hexide and introduce at least two of the alkylene groups (-R-O- wherein R is an alkylene radical, e. g., ethylene, propylene, butylene,

etc.). The alkylene oxide may, however, react with several of the hydroxyl groups of the hexi- .tans or hexides and introduce several oxyal kylene chains. For example, one to four of the hydroxyl groups of the hexitan or one to two of the hydroxyl groups of the hexide may react and form a chain or chains of oxyalkylene groups of two to 20 or more of such groups.

The resulting polyoxyalkylene ethers of the hexitans or hexides may then be reacted with a mono-functional etherification agent or esterification agent to introduce a lipophilic group, e. g., an aliphatic hydrocarbon chain of 8 to 18 or more carbon atoms or the hexitans or hexides may be first esterified or etherified with such agents and the resulting long chain ethers or esters later reacted with an alkylene oxide. Suitable long chain etherification or esterification reactants include normal alkyl halides 0i 8 to 20 carbon atoms, e. g., n-octylchloride, n-dodecyl bromide, n-tetradecylchloride, n-octadecyl bro- -mide, and n-hexadecylbromide,' or a fatty acid halide of 8 to 20 carbon atoms, e. g., octadecoylchloride, dodecoylchloride, tetradecoyl bromide, n-oleyl chloride, etc. The introduction of two oxyalkylene ether groups into the hexitan or hexide is enough to form the products used in accordance with this invention. It is possible that the alkyl halides or acid halides react with the hydroxyl group at the end of the oxyalkylene chain when etherification with alkylene oxides is effected first. However, if the hexitan or hexide is first esterified or etherified with a long chain monofunctional etherification or esterification agent, the lipophilic groups become linked to an acyclic oxygen atom thereof.

When hexitols are dehydrated, they generally "result in a mixture of ring compounds, namely hexitans and hexides, which can be separated by fractional crystallization or extraction. For the purposes of this invention, the ring dehydration products need not be completely separated and mixtures of hexitans and hexides may be utilized to prepare the products used in accordance .45 with this invention.

.3 A class of especially useful products have a structure which is exemplified by the following hexitans and hexide derivative formulae:

wherein in the formulae one of the Rs kyl radical of 8 to 20 carbon atomsor'an acyl radical of the formula RCO-wh'er'ein' R is'of the same order and the other Rs 'arehydrogeir and n is 2 to 20 or more. When only one (CHzCHz-O) n radical is present then should be 6 or more.

The polyoxyalkylene 'ethers or hexitol ring dehydration products are'useful with a wide variety of photographic developing agents. including liy roquinone, chlorohydr'o'quinone, pyrogallol, 'p' rnino'phen'ol,- ferrous-oxalate, N-methylep- :aminopl'ienol sulfate, ZA-dia'minophenbl, N'-'di- 'alkyl phenylenediamine's of the formula their fwfte'r oiiible salt I are the same ordifferent lower lky1 ra cal s, 1:. en, .me hyl. and. t y lflrdiam n benzen 1,4-diaminonaphthalene, p aminodiethyltoluia dine, and mixtures of two or more of such agents, etc.. L

.The developers may containthe.usualsulfites, .e. g.., sodium "sulfite, potassium. .sulfite, potassium .t'ral salts, e. g., sodium bromide; potassiungl jbro- -I"nide;. boric acid, formaldehyde, aldehyde-bisulfitecomplexes, etc.

imetabisulfiteralkalies, eg., sodium or potassium 2.x. carbonate, sodium hydroxidaborax; solubleneu- In making the novel developer solutionsofi this inventionh t is. merely neces ryt l dd-the. poly- ..oxyalkylene 'ethers of the hexitol ringdehydra- .tion products to theaqueous solution intheqsame .manner thattheother ingredients, for example, the sulfites and developing agents, are .,a;dded. The aforesaid ethers readily dissolve or disperse .in aqueous solutions. It is usually most ,co'nvenient to add the aforesaid ethers asja solution. Water :and ethyl alcohol are suitable solvents anda,10% by weightsolution in such solvents affords a practical means for adding the ethers to the developer solution. I I

It has been found that the addition of 0.1;1to 2.5 ram a k e ei her.Qfahexita or a hexide or. a mixture of such compounds to a a v o r solution Sui g o. han e the in,- duction'period of development. lnductionperio'd can be defined a the time necessary to prqduceia id ns v I Q- above we Mor an. bee dii' desired. This reduction is more alrl;eld :ir case of developer solutions which are less ac tive than those which normally have short induction periods.

The invention will be further illustrated by the following examples. The parts are by weight.

Example .A negative type photographic film bearing a gelatino-silver iodobromide emulsion layer was exposed to an object. The exposed film was then divided into parts, one of which was developed in the following developer and one each was developed in the respective developing solutions made by adding 0.5 gram of the respe ctive polyoxyallg'ylene ethersjof heiirita'ns hexides to the developer with the results listed in the following table. In each case the time of development required to produce a density of .02 above fog was measured. JFTli'e results are reported in a relative 'wayas' fractions of the control.

N mthyl ipiaininophenol sulfate grams 0.74 fii dihmsuliite (anhydrous) do 90.4 @Hydroqui'norie do 1.0 Potassium bromide do 0.14 Waterto- 1iter 1.0

Relative Developer Induction Period Unmod ed.

Modified with OI Mqs fie wit D Modified with E A"isi i nanriitan inonolaurat'e' palm-y hyl approximately 20 oxyethylene groups per chains l r b'ita n mat-tease tartareenie strata new!) oxye h enee en s D iq ad vis .2 te

r ma e y 20 c ye h enagmup llqr moleqt Y E is sorbiton trioleate p'olyoxyethyl'cne ether contalninga mately 20 oxyethyl'en groups per molecule inoncchain.

Example II Strips of photographic "paper "comprising "a bar-yta coated paper base'bearing 'a 'ge'lat'ino silver iodobromide "emulsion "layer 'iof a fstandai'd enlargingtype were given" a suitab'lestep' wedge exposure simultaneously on a sector wheePsensitometer of the intermittenttim scaleftype.

f orient the strips was*developed"for75 seconds at '68" F; in a -developing"sdlutioiiofthe-following compositiomand another-"in the saiddveloper modified by the additionof of5 gramprniamiitan monolaurate' pol yoxyetliylene 'etfier containing an average of. 20 oxyethylene group'spefmolebule divided-ill" 3 Challis, Kv'ith" thWeSlflt'S indicated below:

e (anhydrous); d o

1 Developer Example III A perforated motion picture negative type film bearing a gelatino-silver iodobromide emulsion layer is exposed to an object field and divided into two parts. One of the parts is developed in the following solution and the other in the solution modified by the addition of 0.5 gram of mannitan monolaurate polyoxyethylene ether containing an average of 20 oxyethylene groups per molecule divided in 3 chains. The development in each case is for three minutes and twenty seconds at 68 F. and gives the following results:

Sodium sulfite (anhydrous) grams 90.0 p-Phenylenediamine-hydrochloride do 10.0

Strips of positive type motion picture film bearing a gelatino-silver iodobromide emulsion layer were given a suitable step wedge exposure simultaneously on a sector wheel sensitometer of the intermittent time-scale type. One of the strips was developed in a solution of the following composition for three minutes at 68 F. and the other for the same period in said developer modified by the addition of 0.5 gram per liter of mannitan monolaurate polyoxyethylene ether containing an average of 20 oxyethylene groups per molecule divided in 3 chains, with the results listed in the following table:

Example V Strips of a photographic film element bearing a silver iodobromide emulsion layer wherein the binding agent for the silver halide grains is a hydrophilic hydrolyzed ethylene/vinyl acetate copolymer prepared after the manner of the similar polymer used in Example II of U. S. P. 2,397,866 were exposed as in Example II. One film strip was developed in the developer solution of Example II and the other in said solution modified by the addition of sorbitan monolaurate polyoxyethylene ether containing an average of 20 oxyethylene groups per molecule divided in 3 chains for 3 minutes at 68 F. The results are given in the following table:

N-methyl-p-aminophenol sulfate grams 1.2 Sodium sulfite (anhydrous) do 19.0 Hydroquinone do 4.0 Sodium carbonate do 26.0 Potassium bromide do 0.4 Water to liter 1.0

Relative Densities for Equal Exposures Developer Unmodified Modified Example VI A photographic film of the kind described in Example III was exposed as described therein and separated into two parts which were, respectively, developed for.12 minutes at 68 F. in thesolution of the following composition and that modified by the addition of 0.5 of a gram per liter of mannitan monolaurate polyoxyethylene ether containing an average of 20 oxyethylene groups per molecule divided in 3 chains. The results are given in the table.

Relative Densities for E qual Exposures Developer Unmodified 100 Modified 75 Example VII Strips of a standard blue base X-ray film ele ment bearing a light-sensitive iodobromide emulsion layer on each surface weregiven an X-ray exposure under an aluminum step wedge of the usual type and strips of a negative type cine film of the type described in Example III were exposed as described in that example. One strip of each film was developed in (a) a solution of ferrous oxalate (made by pouring 750 cc. of 18.5% potassium oxalate into 250 cc. of 18.5% ferrous sulfate aqueous solution) and (1)) such a solution modified by the addition of 0.5 gram per liter of mannitan monolaurate polyoxyethylene ether containing an average of 20 oxyethylene groups per molecule divided in 3 chains. The developments were continued for four minutes at 68 F. with the following relative densities for equal exposures.

Cine Film X-ray Developer Film Unmodified .i

100 100 Modified 41 89 Example VIII 11 to 3- chains are useful.

iiterpf cempound Az ofiEziample I for'tvvofiafid ofie-hal-f m-i-nutes at 68 E. with the results' listed in the table -below:

Water cc' 5000 jsbdfuin" "s'iilfit' (desiccated) grams 30;:0 'Paralfoiin'aldehytle do 7;5 Potassium metabisulfite do 25 l 3oric acid, crystals do 7.5 I-Iydroquinone do 22.5 Potassium bromide do 1.5 'Cold Water to make liter 1Z0 Developer Speed Gamma Fog Plain 2.40 6. .01 ,140 gmmmrommpie Dpe'rliter; 2.45; =7; .01 Qio gram of A (Example I) per liter. 2.10 r 13 101 -2}'"'gr'anis"of"A'(EXaInpleI)perliter 1395" 14: .01

"Iifplace' of "the snecific dveloping:agerrts described in "the 'aboveex'ar'nples; there may be substit uted' other developing agents "with simil'ar resuits; Likewise other polyoxya'lkylene 'ethersbf "ringuehydrauon products asdiscl'os'eda'bbve' can be substituted for those in the exampleswithsiinil'ar results.

Ir-'1 theabove -examples -the quantity iofoxyethylene groups is -approximate. The'iinvention, hbwever -is not limitedto-the specific pol-yoxyalkylene ether derivatives describe'cl thezexai-nples biit. on the contrary, any .o...such derivatives having the characteristics prescribedabove may :be substituted in like manner. Thus manni- Itan mono-, di-, and tri-oleates, -stearates, -palm-itates, -margarates, etc., containing from 2 to 20 oxyalkivlenegroupswh-ich are distributed in from 7 Similarly the correspending mannides 'containingone-of said fatty acidgroups and 'asimilar amount of oxya-lkylene groups per molecule. Othersuitable compounds including the mannideether esters, e. g., the pal-v mitates, 'margarates,=.fstearatesg 0leates; -1' which contain from 2'' to 20-2 OXYWIkYlGHefLgTOHPSl 'alllfd especially: oxqzethylene groups which.are'distributed in from '1 to-3 chains Man- =nitan;- mannide,-.sorbitan and sorbide ldecyl. dcdecyl'; ttetradecyl, hexadecyl and octadecyl ethers containing the same-*nurnber of: oXyaik-ylene, especially) o'Xy'ethylene' groups are:- also ---.useul.

l The compounds are: useful rin -sim ple andi mixed silve'r halide emulsions of variousrtypes including those containing: silver chloride: only and those containing on'e'or more other "light-sensitive=silver 1 halides, e. g., silver-bromide andsi lveriodide.

It is not known Why the above -ethers confer beneficial resultsinthe 1 development of silver halide images. The compounds alter the-induction' period of development, Perhapsin doingso, laterlt image centers which were not previously developable are made develop'able'. In some cases they "are apparently rendered less- -developable.

age with vazdeveloper solution containinga photographic silver :halide' developing-agentand lfrorn '-0:1 to 2.5 grams of a polyoxyethylene ether-rofva hexitol ring dehydration product per liter of solution.

3. The process of developing a silver halide image with an alkaline developer'solution containing hydroquinone and from 0.1 to 2.5 grams 'of'apolyoxyethylene ether "of a'hexitan per liter of solution.

4. The process of developing a silver halide image with an alkaline developer solution containing hydroquinone and from 0.1 to 2.5 grams of a polyoxyethyleneether'of mannitan monovlaumte per liter of solutionp *5. aqueous de'veloperssolution: containing za photographic: silver i halide I developing-zagent sand from -0.1 :.to- 2.5 grams 20f a :polyoxyalkyleneiether of -a hexitol ring dehydration product :penl-iteri'of solution.

I 6. An- "a'queousalkaline developer-selutioncone -taini-nghydroquinone and 0.1 to 2.5g;gr.amsi ofza polyoxyethylene ether-of .a-hexitol-rring dehydration procl-uct per literoi solution.

'7. An aqueous alkaline developer-solution-cone taining' hydroquinoneand; 0.1 lto 2.5. grams. oi. a polyoxyethylene ether of ahexitan rperrliterr of solution.

8. An aqueous alkalinesdeveloper :solutioncon- -taining hydroquinone and 0.1 to -2.5-'gramsvof' a .p'olyoxyethylene ether of a hexide per-literaof "solution.

9. An aqueous alkaline developersol-u-tionicontaining hydroquinone and 0.1 to 2.5 grams-pf'a polyoxyethylene ether of .mannitan-monolaurate per liter'of solution.

RALPH KINGSLEY BLAIGB.

REFERENCES CITED The'following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,363,493 Baldsiefen Nov. 28, 1944 2,377,375 Russellnlln June 5, 1945 2,400,532 Blake et al May 21, .1946

"Trivelli et' al May/*6; 11947 

1. THE PROCESS OF DEVELOPING A SILVER HALIDE IMAGE WITH A DEVELOPER SOLUTION CONTAINING A PHOTOGRAPHIC SILVER HALIDE DEVELOPING AGENT AND FROM 0.1 TO 2.5 GRAMS OF A POLYXYALKYLENE ETHER OF A HIXITOL RING DEHYDRATION PRODUCT PER LITER OF SOLUTION. 